I've been struggling with this issue for years and haven't talked with anyone about it. I'm 18 years old and I don't have any disorders or other problems; I do really well in school.

Starting about four years ago I started twitching around other people, especially when I'm nervous or angry. Talking to girls is a nightmare. My head shakes from left to right very quickly, almost like I'm shivering. When it happens,I feel a rush of adrenaline or dopamine. It almost feels like an orgasm.

It also happens sometimes when I make eye contact with people, or when people breathe loudly or make sudden movements around me. When girls play with their hair it usually happens.

This has really messed up my life. I avoid making eye contact when talking with people, I don't hang out with friends as much, and I avoid crowds because they set it off. Going to school is hell now, and it's so embarrassing when someone notices. I think it might be some kind of social anxiety, but I do public speaking and I can speak in front of hundreds of people without setting it off...

There are also days when it's much worse. I've figured out that sugar and caffeine make it a lot worse. Sometimes I can talk with a girl and be completely normal, but other times, especially if there are a few other people around, it happens. I need help because I can't go on living like this. Is there some kind of doctor who could diagnose this? Does anyone have advice? I need to fix this.

If it's getting in the way of living a normal life, I'd go talk to your primary care doctor. If they can't help or don't have enough experience, then they can surely point you at the right person to help you.